Method for measuring the liquid crystal efficiency of the liquid crystal layer to the incident

ABSTRACT

The present disclosure providing a method for measuring the liquid crystal efficiency of the liquid crystal layer to the incident, the method includes: keeping the lower polarizing plate unchanged to make the upper polarizing plate and the lower polarizing of the liquid crystal layer in a first state; in the first state, controls the brightness of the screen of the liquid crystal panel be 0 gray and be 255 to measure the brightness of the target position of the liquid crystal panel Lvx and Lvy, respectively; according to the brightness Lvx and the brightness Lvy, determining the liquid crystal efficiency of the liquid crystal layer to the incident. By the above method, the present disclosure could be performed without disassembling the module, and number of the measurements is few and simple, further the efficiency and the accuracy are high.

FIELD OF THE DISCLOSURE

The present disclosure relates to a liquid crystal technology field, and more particularly to a method for measuring the liquid crystal efficiency of the liquid crystal layer to the incident.

BACKGROUND OF THE DISCLOSURE

The most commonly used display mode of the liquid crystal panel includes twisted nematic (TN) mode, vertical alignment (VA) mode and in plain switching (IPS) mode.

Using VA mode as an example: VA display is a normally black mode of vertically aligned and its polarization axis of the upper polarizing plate and the lower polarizing plate is vertical polarizer attachment. The principle of the VA liquid crystal display is based on the characteristic of the light transmittance changed with the size of the applied voltage. After the light through the polarizing plate of the lower substrate (i.e. TFT substrate), the light become linearly polarized light, the direction of the polarization is the direction of the polarization axis of the lower polarizing plate. When no voltage is applied, the light through the liquid crystal will not change the direction of the polarization, and the light will be received through the polarizing plate of the upper substrate (i.e. CF substrate), so that will be a dark state. After applied the voltage, the liquid crystal is deflected alone the alignment direction in the electric field. When the light is through the liquid crystal layer, the linearly polarized light is divided into two beams due to the refraction of the liquid crystal. Also, because of the two different beams of the propagation velocity, after synthesize the two beams, is bound to change the polarization direction of the polarized light. When the incident light reaches the polarizing plate of the upper substrate, the light parallel to the polarization axis direction of the lower polarizing plate can pass through, thus that will be a bright state. In the whole process of display, the liquid crystal has played the role of the light valve controlled by the voltage. This shows that the liquid crystal deflection capability of the polarization direction of the linearly polarized light is very important, it directly affects the result of the penetration.

The liquid crystal efficiency of the liquid crystal layer to the incident light is defined as: the polarized light generated by through the lower polarizing plate and parallel the direction of the polarization axis of the lower polarizing plate, in the maximum gray, exclude the absorb factors of the liquid crystal material, and after through the liquid crystal layer, what percentage of the direction of the polarization of the incident can be deflected 90 degrees by the liquid crystal layer to penetrate out the light. In the prior art, the conventional method for measuring the liquid crystal efficiency is: measuring the transmittance of the liquid crystal panel many times, and excluding other factors of affecting transmittance by calculating, then calculated the liquid efficiency. However, the measurement of this method is more often, the variation in the measurement process is more, and made the approximations, the efficiency and accuracy are low.

SUMMARY OF THE DISCLOSURE

The technical problem of the present disclosure solved is provides a method for measuring the liquid crystal efficiency of the liquid crystal layer to the incident without disassembling the module, and number of the measurements is few and simple, further the efficiency and the accuracy are high.

To solve the above technical problems, one aspect of the present disclosure used is: providing a method for measuring the liquid crystal efficiency of the liquid crystal layer to the incident, the method includes: keeping the lower polarizing plate of the liquid crystal layer unchanged to make the upper polarizing plate and the lower polarizing plate of the liquid crystal are in a first state, the first state is the parallel state of the polarization axis of the upper polarizing plate and the polarization axis of the lower polarizing plate;

in the first state, controls the brightness of the screen of the liquid crystal panel be 0 gray and measures the brightness of the target position of the liquid crystal panel Lvx;

in the first state, controls the brightness of the screen of the liquid crystal panel be 255 gray and measures the brightness of the target position of the liquid crystal panel Lvy;

according to the brightness Lvx and the brightness Lvy, determining the liquid crystal efficiency of the liquid crystal layer to the incident;

wherein, the liquid crystal efficiency of the liquid crystal layer to the incident. A is:

$A = {\left\{ {1 - \frac{Lvy}{Lvx}} \right\} \%}$

or, before the step of keeping the lower polarizing plate of the liquid crystal layer unchanged to make the upper polarizing plate and the lower polarizing plate of the liquid crystal in the first state, includes:

to make the upper polarizer plate and the lower polarizer plate of the liquid crystal layer in a second state, the second state is the vertical state of the polarization axis of the upper polarizing plate and the polarization axis of the lower polarizing plate;

in the second state, controls the brightness of the screen of the liquid crystal panel be 0 gray and measures the brightness of the target position of the liquid crystal panel Lvz;

the step of determining the liquid crystal efficiency of the liquid crystal layer to the incident according to the brightness Lvx and the brightness Lvy includes:

determining the liquid crystal efficiency of the liquid crystal layer to the incident according to the brightness Lvx, the brightness Lvy and the brightness Lvz.

Wherein, the liquid crystal efficiency of the liquid crystal layer to the incident B is:

$B = {\left\{ {1 - \frac{Lvy}{{Lvx} + {Lvz}}} \right\} \%}$

wherein, the step of keeping the lower polarizing plate of the liquid crystal layer unchanged to make the upper polarizing plate and the lower polarizing plate of the liquid crystal in the first state, includes: in the second state, remove the original upper polarizing plate, use the new polarizing plate of the same model of the original upper polarizing plate as the upper polarizing plate, according to the polarizer attach direction corresponding to the original upper polarizer plate deflected 90 degrees and re-posted, the upper polarizing plate and the lower polarizing plate of the liquid crystal layer are in the first state.

In order to solve the above problems, another aspect of the present disclosure used is: providing a method for measuring the liquid crystal efficiency of the liquid crystal layer to the incident, the method includes: keeping the lower polarizing plate of the liquid crystal layer unchanged to make the upper polarizing plate and the lower polarizing plate of the liquid crystal are in a first state, the first state is the parallel state of the polarization axis of the upper polarizing plate and the polarization axis of the lower polarizing plate; in the first state, controls the brightness of the screen of the liquid crystal panel be 0 gray and measures the brightness of the target position of the liquid crystal panel Lvx; in the first state, controls the brightness of the screen of the liquid crystal panel be 255 gray and measures the brightness of the target position of the liquid crystal panel Lvy; according to the brightness Lvx and the brightness Lvy, determining the liquid crystal efficiency of the liquid crystal layer to the incident.

Wherein, the liquid crystal efficiency of the liquid crystal layer to the incident A is:

$A = {\left\{ {1 - \frac{Lvy}{Lvx}} \right\} \%}$

Wherein, before the step of keeping the lower polarizing plate of the liquid crystal layer unchanged to make the upper polarizing plate and the lower polarizing plate of the liquid crystal in the first state, includes: to make the upper polarizer plate and the lower polarizer plate of the liquid crystal layer in a second state, the second state is the vertical state of the polarization axis of the upper polarizing plate and the polarization axis of the lower polarizing plate; in the second state, controls the brightness of the screen of the liquid crystal panel be 0 gray and measures the brightness of the target position of the liquid crystal panel Lvz; the step of determining the liquid crystal efficiency of the liquid crystal layer to the incident according to the brightness Lvx and the brightness Lvy includes: determining the liquid crystal efficiency of the liquid crystal layer to the incident according to the brightness Lvx, the brightness Lvy and the brightness Lvz.

Wherein, the liquid crystal efficiency of the liquid crystal layer to the incident B is:

$B = {\left\{ {1 - \frac{Lvy}{{Lvx} + {Lvz}}} \right\} \%}$

Wherein, the step of keeping the lower polarizing plate of the liquid crystal layer unchanged to make the upper polarizing plate and the lower polarizing plate of the liquid crystal in the first state, includes: in the second state, remove the original upper polarizing plate, use the new polarizing plate of the same model of the original upper polarizing plate as the upper polarizing plate, according to the polarizer attach direction corresponding to the original upper polarizer plate deflected 90 degrees and re-posted, the upper polarizing plate and the lower polarizing plate of the liquid crystal layer are in the first state.

In order to solve the above problems, the other aspect of the present disclosure used is: providing a method for measuring the liquid crystal efficiency of the liquid crystal layer to the predetermined gray incident, wherein, the method includes: keeping the lower polarizing plate of the liquid crystal layer unchanged to make the upper polarizing plate and the lower polarizing plate of the liquid crystal are in a first state, the first state is the parallel state of the polarization axis of the upper polarizing plate and the polarization axis of the lower polarizing plate; in the first state, controls the brightness of the screen of the liquid crystal panel be 0 gray and measures the brightness of the target position of the liquid crystal panel Lvx; in the first state, controls the brightness of the screen of the predetermined color of the liquid crystal panel be predetermined gray and measures the brightness of the target position of the liquid crystal panel Lvy′; according to the brightness Lvx and the brightness Lvy′, determining the liquid crystal efficiency of the liquid crystal layer to the incident of the predetermined color in the predetermined gray.

Wherein, the liquid crystal efficiency of the liquid crystal layer to the incident of the predetermined color in the predetermined gray A′ is:

$A^{\prime} = {\left\{ {1 - \frac{{Lvy}^{\prime}}{Lvx}} \right\} \%}$

Wherein, before the step of keeping the lower polarizing plate of the liquid crystal layer unchanged to make the upper polarizing plate and the lower polarizing plate of the liquid crystal in the first state, includes: to make the upper polarizer plate and the lower polarizer plate of the liquid crystal layer in a second state, the second state is the vertical state of the polarization axis of the upper polarizing plate and the polarization axis of the lower polarizing plate; in the second state, controls the brightness of the screen of the liquid crystal panel be 0 gray and measures the brightness of the target position of the liquid crystal panel Lvz′; the step of determining the liquid crystal efficiency of the liquid crystal layer to the incident according to the brightness Lvx and the brightness Lvy includes: determining the liquid crystal efficiency of the liquid crystal layer to the incident of the predetermined color in the predetermined gray according to the brightness Lvx, the brightness Lvy′ and the brightness Lvz′.

Wherein, the liquid crystal efficiency of the liquid crystal layer to the incident of the predetermined color in the predetermined gray B′ is:

$B^{\prime} = {\left\{ {1 - \frac{{Lvy}^{\prime}}{{Lvx} + {Lvz}^{\prime}}} \right\} \%}$

Wherein, the step of keeping the lower polarizing plate of the liquid crystal layer unchanged to make the upper polarizing plate and the lower polarizing plate of the liquid crystal in the first state, includes: in the second state, remove the original upper polarizing plate, use the new polarizing plate of the same model of the original upper polarizing plate as the upper polarizing plate, according to the polarizer attach direction corresponding to the original upper polarizer plate deflected 90 degrees and re-posted, the upper polarizing plate and the lower polarizing plate of the liquid crystal layer are in the first state.

The beneficial effects of the present disclosure are: the situation is different from the prior art, the present disclosure keeps the lower polarizing plate unchanged to make the upper polarizing plate and the lower polarizing of the liquid crystal layer in a first state, the first state is the parallel state of the polarization axis of the upper polarizing plate and the polarization axis of the lower polarizing plate; in the first state, controls the brightness of the screen of the liquid crystal panel be 0 gray and measures the brightness of the target position of the liquid crystal panel Lvx; in the first state, controls the brightness of the screen of the liquid crystal panel be 255 gray and measures the brightness of the target position of the liquid crystal panel Lvy; according to the brightness Lvx and the brightness Lvy, determining the liquid crystal efficiency of the liquid crystal layer to the incident. By the above method, the measurement of the transmittance in the prior art can be avoided, without disassembling the back light module, the effect of the transmittance fluctuation caused by disassembly can be avoid to measure more accurate and simpler; at the same time, without using the control group, the measured data is measured in the same back light brightness state, the measured data is accurate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of measuring the liquid crystal efficiency in the prior art;

FIG. 2 is another schematic diagram of measuring the liquid crystal efficiency in the prior art;

FIG. 3 is the other schematic diagram of measuring the liquid crystal efficiency in the prior art;

FIG. 4 is a schematic diagram of measuring the liquid crystal efficiency of the liquid crystal layer to the incident of the present disclosure;

FIG. 5 is another schematic diagram of measuring the liquid crystal efficiency of the liquid crystal layer to the incident of the present disclosure;

FIG. 6 is a flow chart of an embodiment of the method for measuring the liquid crystal efficiency of the liquid crystal layer to the incident of the present disclosure;

FIG. 7 is a schematic structure view of the liquid crystal panel in the prior art;

FIG. 8 is a flow chart of another embodiment of the method for measuring the liquid crystal efficiency of the liquid crystal layer to the incident of the present disclosure;

FIG. 9 is a flow chart of an embodiment of the method for measuring the liquid crystal efficiency of the liquid crystal layer to the predetermined gray incident of the present disclosure.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Prior to the detailed description of the present disclosure, first explain the present disclosure related technologies.

One of the method for measuring the liquid crystal efficiency of the liquid crystal layer to the incident in the prior art is as follows:

Refer to FIG. 1 to FIG. 3, the middle is the liquid crystal layer 1, the top of the liquid crystal layer 1 is the upper polarizing plate 2, the bottom of the liquid crystal layer 1 is the lower polarizing plate 3.

As shown in FIG. 1, the first step, measures the normal transmittance of the liquid crystal panel, L is the brightness of the back light source, L₁ is the brightness after through the liquid crystal cell. Accordingly can be drawn:

T=L ₁ /L=η _(lower to natural) *AR*η _(CF)*η_(LC)*η_(upper to polarized)  (1)

T is the total transmittance after through the liquid crystal cell in the FIG. 1, the η_(lower to natural) is the transmittance of the lower polarizing plate to the natural light, the AR is the aperture ratio, η_(CF) is the transmittance of the color filter (CF), η_(LC) is the liquid crystal efficiency, i.e. the transmittance of the liquid crystal layer, η_(upper to polarized) is the transmittance of the upper polarizing plate to the polarized light.

As shown in FIG. 2, the second step, strips the polarizing plate of the upper substrate (i.e. the CF substrate), and measures the transmittance of the liquid crystal panel, L₂ is the brightness after stripping the upper polarizing plate 2 and through the liquid crystal cell, Accordingly can be drawn:

T′=L ₂ /L=η _(lower to natural) *AR*η _(CF)  (2)

Wherein, the T′ is the total transmittance after through the liquid crystal cell in the FIG. 2.

As shown in FIG. 3, the third step, stripping the upper polarizing plate and the lower polarizing plate at same time and measures the transmittance of the liquid crystal panel, L₃ is the brightness after stripping the upper polarizing plate 2 and the lower polarizing plate 3 and through the liquid crystal cell, Accordingly can be drawn:

T″=L ₃ /L=AR*η _(CF)  (3)

Wherein, the T″ is the total transmittance after through the liquid crystal cell.

According to the relationship (1)(2)(3) can be drawn:

T/T′=η _(LC)*η_(upper to polarized)  (4)

T′/T″=η _(lower to natural)  (5)

Suppose the following relationship:

η_(upper to polarized)=2*η_(upper to natural)  (6)

η_(lower to polarized)=2*η_(lower to natural)  (7)

According to the relationship (4)(5)(6)(7), the liquid crystal efficiency can be drawn:

η_(LC) =T*T″/2T′ ²  (8)

By the above calculations, exclude other factors of the transmittance to calculate the efficiency of the liquid crystal.

In the above measurements, measuring the transmittance three times is needed. The number of the measurements is more, because the measurement of the transmittance needs measuring the brightness of the back light and the module respectively, not simultaneous measurement, every time of the disassembly and the human factors will affect the measurement results of the transmittance, the transmittance in the measurement process is susceptible to mutation; the transmittance to the polarizing plate made approximations, the efficiency and the accuracy of the measurement are lowered; the upper polarizing plate and the lower polarizing plate are destroyed, and increase the difficulty and the cost of the re-use of the polarizer attachment.

The present disclosure provides a new measurement principle, and designs a new method for measuring the liquid crystal efficiency, thereby the measurement can be simplified and the measuring efficiency can be increased; simultaneously, the measurement data of the present disclosure without control group and disassembly back light, is measures in the same time period to improve the accuracy and reduce the difficulty and the cost of the re-use of the polarizer attachment.

The accompanying drawings and the following embodiments of the present disclosure will be described in detail.

Introducing the principle of the measurement of the present disclosure first.

The light emitted by the back light source generates the linearly polarized light parallel the direction of the polarization axis of the lower polarizing plate through the lower polarizing plate (TFT substrate). In the maximum gray, removes the absorb factors of the liquid crystal material, after through the liquid crystal layer, because the liquid crystal azimuth or the design of the liquid crystal optical path difference, the liquid crystal is not the completely ½ slide, the liquid crystal layer cannot deflect 90 degrees of all the polarization direction of the incident, thus parallel with the polarization axis of the polarizing plate of the upper substrate (CF substrate) to throughout the light. The liquid crystal efficiency for enhancing transmittance is very important, so it is necessary to evaluate the liquid crystal efficiency of the liquid crystal panel.

The normal VA mode and the IPS mode is the normal black mode, i.e. the direction of the polarization axis of the upper polarizing plate is vertical the direction of the polarization axis of the lower polarizing plate. Suppose the bright state, the liquid crystal efficiency in 255 gray is x %, according to the wave optics theory, all the outgoing light can be decomposed to the deflected linearly polarized light parallel the direction of the polarization axis of the polarizing plate of the upper substrate and vertical the direction of the polarization axis of the polarizing plate of the upper substrate (i.e. the transmission direction and the absorption direction perpendicular to each other). Shown in FIG. 4, if the transmission direction (penetrating axis) has x % of the incident light, the remaining (1−x) % incident is on the absorption direction (absorption axis), i.e. the incident ratio of the penetrating axis and the absorption axis in the bright state as shown in FIG. 4.

In the dark state of the 0 gray, because the IPS contrast is about 1000, the VA mode contrast is over 4000, the brightness of dark state is very low, and the brightness of the bright state is much larger than the dark state. I.e. the direction of the polarization axis of the upper polarizing plate can be considered no light through, the incident light is absorbed by the direction of the absorption axis, and cannot be through, the incident ratio of the penetrating axis and the absorption axis in the dark state as shown in FIG. 5.

Removing the upper polarizing plate, then using the new polarizing plate with same model to re-posted the upper polarizing plate, the polarizer attaching direction is deflected 90 degrees, i.e. the direction of the polarization axis of the upper polarizing plate is parallel the direction of the polarization axis of the lower polarizing plate. This time is the normally white mode, i.e. when no voltage is applied, the liquid crystal does not change the polarization direction of the linearly polarized light, because the polarization axis of the upper polarizing plate is parallel the polarization axis of the lower polarizing plate, the linearly polarized light generated by through the lower polarizing plate is through the transmission direction of the upper polarizing plate directly, is displayed as a white screen, then the liquid crystal efficiency is 100% and the brightness of the measuring panel is Lvx. Then switch to the maximum gray (i.e. 255 gray), the brightness of the measuring panel is Lvy, this brightness is the brightness through the transmission direction of the upper direction and after deflected the liquid crystal, that is the brightness of the absorption direction of the upper polarizing plate when through the original module normally black mode, (Lvy/Lvx) % is the ratio of the incident through the absorption direction of the polarizing plate of the upper substrate, the ratio of the incident through the transmission direction of the polarizing plate of the upper substrate is the liquid crystal efficiency {1−(Lvy/Lvx)}%. When re-posted the upper polarizing plate, the upper polarizing plate deflected 90 degrees, when the penetrating axis of the upper polarizing plate is parallel the penetrating axis of the lower polarizing plate, measures the brightness of the bright state of the 255 gray and the dark state of the 0 gray respectively, i.e. is the (1−x) % incident of the absorption axis in the bright state and is the 100% incident of the absorption axis in the dark state respectively in FIG. 4.

Refer to FIG. 6, FIG. 6 is a flow chart of an embodiment of the method for measuring the liquid crystal efficiency of the liquid crystal layer to the incident of the present disclosure, includes:

Step S101: keeping the lower polarizing plate of the liquid crystal layer unchanged to make the upper polarizing plate and the lower polarizing plate of the liquid crystal layer are in a first state, the first state is the parallel state of the polarization axis of the upper polarizing plate and the polarization axis of the lower polarizing plate.

Usually, the dark state brightness of the normal black mode is very low. E.g. the brightness is 400 and the contrast is 4000, then the dark state brightness is 0.1. Description in the normal black mode, when no voltage is applied, the effect of the liquid crystal to deflect the linearly polarized light can be ignored.

Refer to FIG. 7, FIG. 7 is a schematic structure view of the liquid crystal panel, the liquid crystal panel from top to bottom including a upper polarizing plate 11, a upper substrate 12, a liquid crystal layer 13, a lower substrate 14, a lower polarizing plate 15 and a back light module 16.

The first state is the parallel state of the polarization axis of the upper polarizing plate and the polarization axis of the lower polarizing plate, keeps the lower polarizing plate of the liquid crystal layer unchanged to make the upper polarizing plate and the lower polarizing plate of the liquid crystal layer in the first state, that is the lower polarizing plate 15 and the back light module 16 are without dismantling can remain intact, in the case of need, makes the upper polarizing plate and the lower polarizing plate of the liquid crystal layer in the first state, can only change the upper polarizer 11, the polarization axis of the upper polarizing plate is changed 90 degrees, the upper polarizing plate and the lower polarizing plate are in the first state.

For the VA display mode, the IPS display mode and the TN display mode, the upper polarizing plate and the lower polarizing plate are polarization axis vertical attachment, and referred to as the second state.

In this case, the step S101 can be: in the second state, remove the original upper polarizing plate, use the new polarizing plate of the same model of the original upper polarizing plate as the upper polarizing plate, according to the polarizer attach direction corresponding to the original upper polarizer plate deflected 90 degrees and re-posted, the upper polarizing plate and the lower polarizing plate of the liquid crystal layer are in the first state.

Have to be aware of is: first, the re-posted upper polarizing plate type is closer to the polarizing plate and the original panel, the effect of the polarizing plate to the result is less; the polarizing plate with the same type and the same batch of the polarizing plate of the original panel is preferred. Second, when re-posting, the accuracy is required, if the manual polarizing attachment, it can give a signal of the liquid crystal back light module when attaching, then attaching alone the direction of the pixel arranged. Third, if choose the machine to attach, because the size problem, the lower polarizing with the same type and the same batch attach to the upper substrate can be chosen; or cutting the upper polarizing plate and then attaching.

By the above method, the measurement of the transmittance in the prior art can be avoided, without disassembling the back light module, the effect of the transmittance fluctuation caused by disassembly can be avoid to measure more accurate and simpler; at the same time, without using the control group, the measured data is measured in the same back light brightness state, the measured data is accurate.

Step S102: in the first state, controls the brightness of the screen of the liquid crystal panel be 0 gray and measures the brightness of the target position of the liquid crystal panel Lvx.

Step S103: in the first state, controls the brightness of the screen of the liquid crystal panel be 255 gray and measures the brightness of the target position of the liquid crystal panel Lvy.

Step S104: according to the brightness Lvx and the brightness Lvy, determining the liquid crystal efficiency of the liquid crystal layer to the incident.

The brightness Lvx is the normally white mode, i.e. when no voltage is applied, the liquid crystal does not change the polarization direction of the linearly polarized light, because the polarization axis of the upper polarizing plate is parallel the polarization axis of the lower polarizing plate, the linearly polarized light generated by through the lower polarizing plate is through the transmission direction of the upper polarizing plate directly, is displayed as a white screen, then the liquid crystal efficiency is 100%.

The brightness Lvy is switching to the maximum gray (i.e. 255 gray), this brightness is the brightness through the transmission direction of the upper direction and after deflected the liquid crystal that is the brightness of the absorption direction of the upper polarizing plate when through the original module normally black mode.

If there are some other aspects of the correction factor, combine with the correction factor, the brightness Lvx and the brightness Lvy, or to combine with the experience, or combined by the given formula etc., i.e. the liquid crystal efficiency of the liquid crystal layer to the incident can be determined.

In an embodiment, if the impact of the correction factor or other factors are ignored, the liquid crystal efficiency of the liquid crystal layer to the incident A is:

$A = {\left\{ {1 - \frac{Lvy}{Lvx}} \right\} \%}$

If the contract of the liquid crystal panel is very low, when the brightness of the dark state is very high, described in the normally black mode, when the voltage is not applied, the liquid crystal to linearly polarized light has the deflection effect, when no voltage applied the liquid crystal efficiency is not 100%, the brightness of the dark state Lvz in the normally black mode is needed to measure first, then measuring with the above method. Refer to FIG. 8, the step S101 further can include: step S105 and step S106.

Step S105: the upper polarizing plate and the lower polarizing of the liquid crystal layer in the second state, the second state is the vertical state of the polarization axis of the upper polarizing plate and the lower polarizing plate.

Step S106: in the second state, controls the brightness of the screen of the liquid crystal panel be 0 gray and measures the brightness of the target position of the liquid crystal panel Lvz;

At this step S104, specifically: according to the brightness Lvx, the brightness Lvy and the brightness Lvz, determining the liquid crystal efficiency of the liquid crystal layer to the incident.

If there are some other aspects of the correction factor, combine with the correction factor, the brightness Lvx, the brightness Lvy and the brightness Lvz, or to combine with the experience, or combined by the given formula etc., i.e. the liquid crystal efficiency of the liquid crystal layer to the incident can be determined.

Wherein, if the impact of the correction factor or other factors are ignored, the liquid crystal efficiency of the liquid crystal layer to the incident B is:

$B = {\left\{ {1 - \frac{Lvy}{{Lvx} + {Lvz}}} \right\} \%}$

Wherein, the step S101 can be: in the second state, remove the original upper polarizing plate, use the new polarizing plate of the same model of the original upper polarizing plate as the upper polarizing plate, according to the polarizer attach direction corresponding to the original upper polarizer plate deflected 90 degrees and re-posted, the upper polarizing plate and the lower polarizing plate of the liquid crystal layer are in the first state.

The following specific experimental data to illustrate the beneficial effects of the present disclosure. Compare the prior art shown in FIG. 1 to FIG. 3. Table 1 shows the test data measured the liquid crystal efficiency by the compared method, table 2 shows the test data measured the liquid crystal efficiency without considering the brightness of the dark state, and table 3 shows the test data measured the liquid crystal efficiency with considering the brightness of the dark state.

TABLE 1 Comparative Method First Second Third Fourth time time time time Original module 308.6 312.7 280.9 292.1 BLU 4566.3 4601.6 4217 4374.5 Original transmission  6.76%  6.80%  6.66%  6.68% module Remove the upper 413.9 418.8 381.5 396.2 polarizing plate BLU 4564.5 4600.2 4210.5 4368.5 Remove the  9.07%  9.10%  9.06%  9.07% transmission of the upper polarizing plate Remove the upper 928.7 934.2 858 887.7 polarizing plate and the lower polarizing plate BLU 4559.3 4585.7 4194.6 4360.4 Remove the 20.37% 20.37% 20.46% 20.36% transmission of the upper polarizing plate and the lower polarizing plate Liquid crystal efficiency 83.70% 83.50%   83% 82.60%

TABLE 2 The method of the present disclosure( without considering the dark state ) First Second Third Fourth time time time time Remove the upper polarizing plate 76.3 75.1 72.2 72.9 and attach parallel 255 gray Remove the upper polarizing plate 392.3 394.9 362.5 373.4 and attach parallel 0 gray Liquid crystal efficiency 80.50% 81% 80.10% 80.50%

TABLE 3 The method of the present disclosure ( considering the dark state ) First Second Third Fourth time time time time Dark state brightness of the 0.058 0.06 0.05 0.053 original module Remove the upper polarizing plate 76.3 75.1 72.2 72.9 and attach parallel 255 gray Remove the upper polarizing plate 392.3 394.9 362.5 373.4 and attach parallel 0 gray Liquid crystal efficiency 80.60% 81% 80.10% 80.50%

According to table 1 to table 3, the two methods show the measured liquid crystal efficiency is close, and the contrast of the normally black mode is very high, i.e. when the brightness of the dark state is very low, the effect to the liquid crystal efficiency can be ignored.

the present disclosure keeps the lower polarizing plate unchanged to make the upper polarizing plate and the lower polarizing of the liquid crystal layer in a first state, the first state is the parallel state of the polarization axis of the upper polarizing plate and the polarization axis of the lower polarizing plate; in the first state, controls the brightness of the screen of the liquid crystal panel be 0 gray and measures the brightness of the target position of the liquid crystal panel Lvx; in the first state, controls the brightness of the screen of the liquid crystal panel be 255 gray and measures the brightness of the target position of the liquid crystal panel Lvy; according to the brightness Lvx and the brightness Lvy, determining the liquid crystal efficiency of the liquid crystal layer to the incident. By the above method, the measurement of the transmittance in the prior art can be avoided, without disassembling the back light module, the effect of the transmittance fluctuation caused by disassembly can be avoid to measure more accurate and simpler; at the same time, without using the control group, the measured data is measured in the same back light brightness state, the measured data is accurate.

Refer to FIG. 9, FIG. 9 is a flow chart of an embodiment of the method for measuring the liquid crystal efficiency of the liquid crystal layer to the predetermined gray incident of the present disclosure, the method of the present embodiment is basically the same as the method described above, see the detailed description of the above method, this is no longer dwell in detail; the difference is: first, change the 255 gray in the above method to be a predetermined gray, that is possible to measure the brightness Lvy′ of the liquid crystal panel in any predetermined gray which can measure the liquid crystal efficiency in the predetermined gray; second, change the incident in the above method to be a predetermined color, that is possible to measure any predetermined color and the liquid crystal efficiency in the predetermined gray. The method including:

Step S201: keeping the lower polarizing plate of the liquid crystal layer unchanged to make the upper polarizing plate and the lower polarizing plate of the liquid crystal are in a first state, the first state is the parallel state of the polarization axis of the upper polarizing plate and the polarization axis of the lower polarizing plate.

Step S202: in the first state, controls the brightness of the screen of the liquid crystal panel be 0 gray and measures the brightness of the target position of the liquid crystal panel Lvx.

Step S203: in the first state, controls the brightness of the screen of the predetermined color of the liquid crystal panel be predetermined gray and measures the brightness of the target position of the liquid crystal panel Lvy′.

Step S204: according to the brightness Lvx and the brightness Lvy′, determining the liquid crystal efficiency of the liquid crystal layer to the incident of the predetermined color in the predetermined gray.

By the above method, it can measure any color and the liquid crystal efficiency of any gray.

Wherein, the liquid crystal efficiency of the liquid crystal layer to the incident of the predetermined color in the predetermined gray A′ is:

$A^{\prime} = {\left\{ {1 - \frac{{Lvy}^{\prime}}{Lvx}} \right\} \%}$

Wherein, before the step S201, may include:

A. the upper polarizing plate and the lower polarizing of the liquid crystal layer in the second state, the second state is the vertical state of the polarization axis of the upper polarizing plate and the lower polarizing plate.

B. in the second state, controls the brightness of the screen of the liquid crystal panel be 0 gray and measures the brightness of the target position of the liquid crystal panel Lvz′.

At this step S204, specifically: according to the brightness Lvx, the brightness Lvy′ and the brightness Lvz′, determining the liquid crystal efficiency of the liquid crystal layer to the incident.

Wherein, the liquid crystal efficiency of the liquid crystal layer to the incident of the predetermined color in the predetermined gray B′ is:

$B^{\prime} = {\left\{ {1 - \frac{{Lvy}^{\prime}}{{Lvx} + {Lvz}^{\prime}}} \right\} \%}$

Wherein, the step S201 can include: in the second state, remove the original upper polarizing plate, use the new polarizing plate of the same model of the original upper polarizing plate as the upper polarizing plate, according to the polarizer attach direction corresponding to the original upper polarizer plate deflected 90 degrees and re-posted, the upper polarizing plate and the lower polarizing plate of the liquid crystal layer are in the first state.

Above are only embodiments of the present disclosure is not patented and therefore limit the scope of the disclosure, all the contents of the present disclosure utilize the specification made equivalent structures or equivalent process transformation, either directly or indirectly related technologies used in other areas are included in the patent empathy scope of the disclosure. 

What is claimed is:
 1. A method for measuring the liquid crystal efficiency of the liquid crystal layer to the incident, wherein, the method comprises: keeping the lower polarizing plate of the liquid crystal layer unchanged to make the upper polarizing plate and the lower polarizing plate of the liquid crystal are in a first state, the first state is the parallel state of the polarization axis of the upper polarizing plate and the polarization axis of the lower polarizing plate; In the first state, controls the brightness of the screen of the liquid crystal panel be 0 gray and measures the brightness of the target position of the liquid crystal panel Lvx; in the first state, controls the brightness of the screen of the liquid crystal panel be 255 gray and measures the brightness of the target position of the liquid crystal panel Lvy; according to the brightness Lvx and the brightness Lvy, determining the liquid crystal efficiency of the liquid crystal layer to the incident; wherein, the liquid crystal efficiency of the liquid crystal layer to the incident A is: $A = {\left\{ {1 - \frac{Lvy}{Lvx}} \right\} \%}$ or, before the step of keeping the lower polarizing plate of the liquid crystal layer unchanged to make the upper polarizing plate and the lower polarizing plate of the liquid crystal in the first state, comprises: to make the upper polarizer plate and the lower polarizer plate of the liquid crystal layer in a second state, the second state is the vertical state of the polarization axis of the upper polarizing plate and the polarization axis of the lower polarizing plate; in the second state, controls the brightness of the screen of the liquid crystal panel be 0 gray and measures the brightness of the target position of the liquid crystal panel Lvz; the step of determining the liquid crystal efficiency of the liquid crystal layer to the incident according to the brightness Lvx and the brightness Lvy comprises: determining the liquid crystal efficiency of the liquid crystal layer to the incident according to the brightness Lvx, the brightness Lvy and the brightness Lvz.
 2. The method according to claim 1, wherein, the liquid crystal efficiency of the liquid crystal layer to the incident B is: $B = {\left\{ {1 - \frac{Lvy}{{Lvx} + {Lvz}}} \right\} \%}$
 3. The method according to claim 1, wherein, the step of keeping the lower polarizing plate of the liquid crystal layer unchanged to make the upper polarizing plate and the lower polarizing plate of the liquid crystal in the first state, comprises: in the second state, remove the original upper polarizing plate, use the new polarizing plate of the same model of the original upper polarizing plate as the upper polarizing plate, according to the polarizer attach direction corresponding to the original upper polarizer plate deflected 90 degrees and re-posted, the upper polarizing plate and the lower polarizing plate of the liquid crystal layer are in the first state.
 4. A method for measuring the liquid crystal efficiency of the liquid crystal layer to the incident, wherein, the method comprises: keeping the lower polarizing plate of the liquid crystal layer unchanged to make the upper polarizing plate and the lower polarizing plate of the liquid crystal are in a first state, the first state is the parallel state of the polarization axis of the upper polarizing plate and the polarization axis of the lower polarizing plate; In the first state, controls the brightness of the screen of the liquid crystal panel be 0 gray and measures the brightness of the target position of the liquid crystal panel Lvx; in the first state, controls the brightness of the screen of the liquid crystal panel be 255 gray and measures the brightness of the target position of the liquid crystal panel Lvy; according to the brightness Lvx and the brightness Lvy, determining the liquid crystal efficiency of the liquid crystal layer to the incident.
 5. The method according to claim 4, wherein, the liquid crystal efficiency of the liquid crystal layer to the incident A is: $A = {\left\{ {1 - \frac{Lvy}{Lvx}} \right\} \%}$
 6. The method according to claim 4, wherein, before the step of keeping the lower polarizing plate of the liquid crystal layer unchanged to make the upper polarizing plate and the lower polarizing plate of the liquid crystal in the first state, comprises: to make the upper polarizer plate and the lower polarizer plate of the liquid crystal layer in a second state, the second state is the vertical state of the polarization axis of the upper polarizing plate and the polarization axis of the lower polarizing plate; in the second state, controls the brightness of the screen of the liquid crystal panel be 0 gray and measures the brightness of the target position of the liquid crystal panel Lvz; the step of determining the liquid crystal efficiency of the liquid crystal layer to the incident according to the brightness Lvx and the brightness Lvy comprises: determining the liquid crystal efficiency of the liquid crystal layer to the incident according to the brightness Lvx, the brightness Lvy and the brightness Lvz.
 7. The method according to claim 6, wherein, the liquid crystal efficiency of the liquid crystal layer to the incident B is: $B = {\left\{ {1 - \frac{Lvy}{{Lvx} + {Lvz}}} \right\} \%}$
 8. The method according to claim 6, wherein, the step of keeping the lower polarizing plate of the liquid crystal layer unchanged to make the upper polarizing plate and the lower polarizing plate of the liquid crystal in the first state, comprises: In the second state, remove the original upper polarizing plate, use the new polarizing plate of the same model of the original upper polarizing plate as the upper polarizing plate, according to the polarizer attach direction corresponding to the original upper polarizer plate deflected 90 degrees and re-posted, the upper polarizing plate and the lower polarizing plate of the liquid crystal layer are in the first state.
 9. A method for measuring the liquid crystal efficiency of the liquid crystal layer to the predetermined gray incident, wherein, the method comprises: keeping the lower polarizing plate of the liquid crystal layer unchanged to make the upper polarizing plate and the lower polarizing plate of the liquid crystal are in a first state, the first state is the parallel state of the polarization axis of the upper polarizing plate and the polarization axis of the lower polarizing plate; In the first state, controls the brightness of the screen of the liquid crystal panel be 0 gray and measures the brightness of the target position of the liquid crystal panel Lvx; in the first state, controls the brightness of the screen of the predetermined color of the liquid crystal panel be predetermined gray and measures the brightness of the target position of the liquid crystal panel Lvy′; according to the brightness Lvx and the brightness Lvy′, determining the liquid crystal efficiency of the liquid crystal layer to the incident of the predetermined color in the predetermined gray.
 10. The method according to claim 9, wherein, the liquid crystal efficiency of the liquid crystal layer to the incident of the predetermined color in the predetermined gray A′ is: $A^{\prime} = {\left\{ {1 - \frac{{Lvy}^{\prime}}{Lvx}} \right\} \%}$
 11. The method according to claim 9, wherein, before the step of keeping the lower polarizing plate of the liquid crystal layer unchanged to make the upper polarizing plate and the lower polarizing plate of the liquid crystal in the first state, comprises: to make the upper polarizer plate and the lower polarizer plate of the liquid crystal layer in a second state, the second state is the vertical state of the polarization axis of the upper polarizing plate and the polarization axis of the lower polarizing plate; in the second state, controls the brightness of the screen of the liquid crystal panel be 0 gray and measures the brightness of the target position of the liquid crystal panel Lvz′; the step of determining the liquid crystal efficiency of the liquid crystal layer to the incident according to the brightness Lvx and the brightness Lvy comprises: determining the liquid crystal efficiency of the liquid crystal layer to the incident of the predetermined color in the predetermined gray according to the brightness Lvx, the brightness Lvy′ and the brightness Lvz′.
 12. The method according to claim 11, wherein, the liquid crystal efficiency of the liquid crystal layer to the incident of the predetermined color in the predetermined gray B′ is: $B^{\prime} = {\left\{ {1 - \frac{{Lvy}^{\prime}}{{Lvx} + {Lvz}^{\prime}}} \right\} \%}$
 13. The method according to claim 11, wherein, the step of keeping the lower polarizing plate of the liquid crystal layer unchanged to make the upper polarizing plate and the lower polarizing plate of the liquid crystal in the first state, comprises: In the second state, remove the original upper polarizing plate, use the new polarizing plate of the same model of the original upper polarizing plate as the upper polarizing plate, according to the polarizer attach direction corresponding to the original upper polarizer plate deflected 90 degrees and re-posted, the upper polarizing plate and the lower polarizing plate of the liquid crystal layer are in the first state. 